Lost in the World (2015)

Whitney is a police officer whose long-term girlfriend Palesa, is violently raped and murdered. When Whitney finds out she goes on a manhunt to find the perpetrators. Her commanding officer takes her off the case because she's getting too emotional. Whitney takes some time off and goes on a binge of drugs and alcohol. Through one of her binges she discovers that one of the effects of heroine is hallucinating. She begins to explore it more and more, the more vibrant the hallucinations the more she needs to take. When getting back to work she discovers that her colleagues did not find the perpetrators and in fact were told to close the case. As the subject matter didn't coincide with her Captain's mandate. She then takes it upon herself to solve the crime and in doing so is fired. She does however solve the case and figures out who killed Palesa, they were four men. Subsequently she hunts them down but due to her drug abuse she isn't as careful as she should have been and is caught. The judge determines that she should not be sent to prison but instead a mental institution.